Given a signal name, a description, and a handler body, this registers a signal handler and returns the Signallable instance.
Given a signal name, a description, and a handler body, this registers a signal handler and returns the Signallable instance. The signal handler registry is thereafter available by calling SignalManager.info(), or sending SIGINFO to the manager will dump it to console.
Same as the other apply, but an open signal is found for you.